Testing of high frequency devices (circuits) requires that the user first characterize the test setup. Once the effects of the test setup are known they can be eliminated from a measured response to determine the response of the device under test. Commonly, all the fixturing associated with a test setup is assumed to be a linear network. A well known calibration standard is inserted into the test setup and a sine wave of a first frequency is applied to the test setup. The response of the calibration standard and test setup together are measured. The test setup is characterized by a plurality of coefficients that describe the test setup's effect on the input and output signals. This is repeated for a number of frequencies and may be repeated for several calibration standards. The device under test is then inserted into the test setup and the response to a sine wave input at a number of frequencies is measured. The measured response is adjusted by the known properties of test setup and the device under test is characterized. Unfortunately, real input signals typically are not sine waves, but have multiple frequencies. Real input signals are modulated or imperfect square waves. As a result a user does not obtain a picture of a real output when using sine wave inputs. In addition, it has been found that real devices (circuits) often have non-linear responses to real-world signals. When real devices are tested with sine waves, an inaccurate model of the device is formed.
Thus there exists a need for a method of testing electronic devices that provides the user with a real output and characterizes the device under operating conditions.